[Effect of Enterued administration on the intestinal absorption of orally active cefem antibiotics]

The effect of simultaneous administration of Enterued, an elemental diet, which is composed of oligopeptides (egg white hydrolyzate), on the orally active cefems was investigated. Ceftibuten (CETB) administered together with Enterued to man was excreted slower in the urine. AUC from the plasma concentrations of CETB after the oral administration with Enterued was markedly decreased compared to that without Enterued in rat. In contrast, neither urinary excretion of cephalexin (CEX) in man nor the AUC from the plasma profile of CEX in rat was changed by Enterued. Furthermore, the disappearance, tissue accumulation, net absorption of CETB from the rat jejunal loop were significantly inhibited by Enterued. However, the net absorption of CEX has no alternation in the presence of Enterued, although the apparent disappearance decreased on the basis of the diminishment of tissue accumulation. Additionally, Hepan ED, which is an elementary diet composed of amino acids, and the mineral solution containing neither peptides nor vitamins have also exhibited the decreasing effect on the CETB absorption behaviour. These results suggested that the inhibitory effects of Enterued on the absorption of these antibiotics were not due to the inhibition of peptide-transport systems.